This disclosure relates generally to methods and devices for controlling and directing fluid flow. More particularly, this disclosure relates to a valve arrangement that controls fluid flow communication.
A wide variety of valve arrangements have been utilized for controlling and directing fluid flow. Some known valve arrangements include an electrical solenoid valve that operates as a pilot valve to control a primary valve passageway. In traditional arrangements, the pilot valve is electronically operated to communicate an operating fluid flow, which in turn controls a primary working fluid flow; the operating fluid flow and the working fluid flow deriving from the same pressure source.
In general, improvement has been sought with respect to such valve arrangements, generally to: provide enhanced fail-safe operations with regards to permitting fluid flow under specific conditions, provide an arrangement having separate operating and working fluid flows, and provide an arrangement where the working fluid is isolated from the operating valve components.
In one aspect, the present invention relates to a valve arrangement for controlling fluid flow of a working fluid. The valve arrangement includes first, second and third pressure chambers. A solenoid valve provides fluid communication between the first and second pressure chambers. A central shaft having a passage provides fluid communication between the second and third pressure chambers. The valve arrangement utilizes an operating fluid to control operation of the valve arrangement.
Another aspect of the present invention relates to a valve arrangement having a shaft positionable between and first position and a second position. The first and second positions correspond to the closed and open states of the valve arrangement. The shaft is biased to the first position when a solenoid valve is de-energized. The shaft is biased to the second position when the normally-open solenoid valve is energized and an operating fluid is supplied to the valve arrangement.
Yet another aspect of the present invention relates to a method of controlling fluid flow of a working fluid.